Between January 1989 and February 1995 a group of 47 consecutive infants aged 31-180 days (mean 83.5 +/- 48.8 days) with various cyanotic heart diseases and poor intracardiac mixing underwent balloon atrial septostomy (BAS) under two-dimensional (2D) echocardiographic control in the procedure room or intensive care unit. Diagnoses were 27 cases of transposition of the great arteries (TGA), 1 mitral atresia, 9 tricuspid atresia, 7 critical pulmonary stenosis with hypoplastic right ventricle, 3 pulmonary atresia with intact interventricular septum, and 1 total anomalous pulmonary venous return. A standard subcostal view was used mainly to delineate the interatrial septum and to guide the balloon catheter. The creating (tearing) of the atrial septal defect was seen clearly during the procedure, and the 2D echocardiographic imaging was helpful for assessing the adequacy of the BAS at the end of the procedure. The results were good (5-9 mm in diameter) with no significant complications. The 2D echocardiographic scans showed no significant changes in the created atrial hole sizes during the follow-up of 1-6 months. We conclude that BAS under 2D echocardiographic control can be performed successfully and safely in infants with cyanotic congenital heart disease up to 6 months of age. This method should be considered for palliation, avoidance of surgery, or allowing the patient to survive until an appropriate time for corrective surgery.

One of the important complications of transcatheter occlusion of the patent duct by insertion of either the Rashkind double umbrella or coil devices is intravascular haemolysis, particularly the severe form which occurs in 0.5-0.6% of cases. The incidence of subclinical or mild intravascular haemolysis including morphologic changes in the red cells, however, is not known, especially in the group of patients with residual shunt. We studied laboratory and haematologic changes in 37 patients subsequent to transcatheter occlusion. Their ages ranged from 2 years 2 months to 11 years 8 months (6.2 + 2.7 years), and the duration of occlusion had ranged from 1 month to 2 years 11 months (1.24 + 0.89 years). In 30 cases we had used the Rashkind double umbrella device, and nine of these patients (30%) had a residual shunt. The other seven ducts were closed with detachable coils, and five of these cases (71%) had residual shunting. There was evidence of mild or subclinical intravascular haemolysis in almost half the cases, although no patient developed acute intravascular haemolysis. Fragmented red cells, blur cells and spherocytes from blood smears were found in up to one-third of the overall series, with no differences found according to persistence of shunting. Haemosiderin was found in the urine of the group with residual shunting and in 13-23% of those with complete occlusion. Serum hypohaptoglobin was found in 9-13% of the patients with a residual shunt, and in 9-23% of those with complete occlusion. Four of the patients had haptoglobin levels < 50 mg/dl. There were no patients with reticulocytes counts > 2% in the blood smears. We conclude that subclinical or mild intravascular haemolysis, along with morphologic changes in the red blood cells, are significant findings subsequent to occlusion of the patent arterial duct with either the Rashkind double umbrella or detachable coils.